According to a Financial Times report the bank is estimating that up to half of its staff could fall ill at the peak of the next flu pandemic. The 50% figure is higher than official forecasts, including estimates from the World Health Organisation (WHO) which is expected to advise companies to plan for 25% absence.

HSBC has 253,000 staff worldwide across 77 countries. Its business in Asia was affected by the outbreak of the SARS virus in 2003.

Concerns about the spread of bird flu have escalated following the recent outbreak in Turkey. The H5N1 strain of bird flu has killed around 74 people in China and Southeast Asia since 2003, but the virus has shifted westwards to Turkey where three children have died from the virus and 14 people had been confirmed with bird flu infections.

Bob Piggott, head of group crisis management at HSBC, told the FT that the bank was devising ways to cope with 50% of normal staff during a pandemic wave that could last for up to three months.

Piggott says in addition to staff who stayed at home with the flu, many employees would be off recovering from secondary infections and other would be absent caring for family members.

He told reporters that HSBC was also preparing for staff to work from home using video link and teleconference facilities and was planning for office cleaning once an hour in an effort to limit infection.

Piggott says several other banks were also stepping up their preparations for a flu pandemic and moving towards similar estimates for absences.

In December, the US Futures Industry Association hosted a gathering of exchanges, financial firms, and public health and city/state agencies to discuss contingency planning issues in the event of a pandemic. The event, which was closed to the press, asked how avian flu might affect the running of futures and options markets amid estimates of 25% to 40% absenteeism.